Cyclophotocoagulation in Glaucoma

Modified Settings for Transscleral Cyclophotocoagulation of the Ciliary Body in Glaucoma : A Randomized Controlled Trial

Transscleral cyclophotocoagulation of the ciliary body is an effective technique to reduce intraocular pressure in case of glaucoma. Due to concerns over complications, the main indications for this second-line treatment are refractory glaucoma medication / surgery and low visual prognosis. The 2000 milliwatts (mW) for 2 seconds settings are used by the majority of researchers and clinicians according to the published literature. Some have proposed using 1250 mW for 4 seconds to improve the use of this medical procedure.

The aim of this study is to determine how different parameters affect the efficacy of the treatment. This is a prospective double-blinded randomized controlled trial comparing two groups, the experimental group using 1250 mW for 4 seconds and the control group using 2000 mW for 2 seconds.

Study Overview

• Status: Completed
• Conditions: Glaucoma
• Intervention / Treatment: Procedure: Cyclophotocoagulation protocol; Procedure: Conventional cyclophotocoagulation; Procedure: Modified cyclophotocoagulation

• Study Type: Interventional
• Enrollment (Actual): 44
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Québec, Canada, G1S 4L8
    • Centre universitaire d'ophtalmologie, Hôpital du Saint-Sacrement. CHU de Québec

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Patients with poorly controlled high pressure glaucoma
• Cyclophotocoagulation necessary to prevent visual loss
• Cyclophotocoagulation necessary to prevent or to reduce ocular discomfort

Exclusion Criteria:

• Patient has already undergone a cyclophotocoagulation or cryotherapy treatment in the same eye for glaucoma
• Patients receiving concomitant treatment the same day as the intervention
• Patient not able to follow the prescribed post-operative treatment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Diode laser using conventional settings; The cyclophotocoagulation protocol is used with the conventional cyclophotocoagulation settings of 2000 mW for 2 seconds.	Procedure: Cyclophotocoagulation protocol; Intravenous route is installed; Retrobulbar anaesthesia : 50% xylocaine (2%) + 50% bupivicaine; Parameters set for laser treatment (1250mW-4seconds or 2000mW-2 seconds depending on the assigned group); Pars plana measurement using transillumination (if needed); Laser treatment applied approximately 1mm post to limbus; Dexamethasone 0,5 mg subconjunctival injection; Post-op regimen: Prednisolone 1% qid x 4 weeks, Atropine 1% bid x 2 weeks + Erythromycin ointment + patch x 6h; Procedure: Conventional cyclophotocoagulation; 1250 mW for 4 seconds.
Experimental: Diode laser using modified settings; The cyclophotocoagulation protocol is used with the modified cyclophotocoagulation settings of 1250 mW for 4 seconds.	Procedure: Cyclophotocoagulation protocol; Intravenous route is installed; Retrobulbar anaesthesia : 50% xylocaine (2%) + 50% bupivicaine; Parameters set for laser treatment (1250mW-4seconds or 2000mW-2 seconds depending on the assigned group); Pars plana measurement using transillumination (if needed); Laser treatment applied approximately 1mm post to limbus; Dexamethasone 0,5 mg subconjunctival injection; Post-op regimen: Prednisolone 1% qid x 4 weeks, Atropine 1% bid x 2 weeks + Erythromycin ointment + patch x 6h; Procedure: Modified cyclophotocoagulation; 2000 mW for 2 seconds.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraocular pressure (IOP) evolution	The intraocular pressure is measured to determine the efficacy of treatment during follow-up compared to the baseline IOP.	1h, 1 month, 6 months, 12 months, 18 months and 24 months post-op

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Presence of complications	Assessment of complications (if applicable).	During the intervention, 1 month, 6 months, 12 months, 18 months, 24 months post-op
Use of medication	Assessment of the topical and oral glaucoma medication at baseline and after treatment	1 month, 6 months, 12 months, 18 months and 24 months post-op
Retreatment	The clinician will assess the need for retreatment based on clinical experience.	From the initial treatment up to the last visit (24 months)
Visual acuity	The visual acuity will be assessed at baseline and each subsequent visit	1 month, 6 months, 12 months, 18 months and 24 months post-op

Collaborators and Investigators

• Sponsor: CHU de Quebec-Universite Laval
• Investigators: Principal Investigator: Andrew Toren, Doctor, Centre de recherche du CHU de Québec : Université Laval

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2016
• Primary Completion (Actual): August 1, 2023
• Study Completion (Actual): August 1, 2023

Study Registration Dates

• First Submitted: July 18, 2016
• First Submitted That Met QC Criteria: August 22, 2016
• First Posted (Estimated): August 23, 2016

Study Record Updates

• Last Update Posted (Actual): September 11, 2023
• Last Update Submitted That Met QC Criteria: September 8, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Glaucoma
• Other Study ID Numbers: 2015-2212

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO